Quiz 1 _ Intro to Pharmacology

pharmacokinetics definition

what the body does to the drug

critical concentration definition

does of drug that is not too much or too little

components for swallowed drugs

ADME!

• absorption

• distribution

• metabolism

• excretion

what happens during the absorption portion of pharmacokinetics?

drug is absorbed by the stomach and small intestines

factors that affect absorption

• drug formulation — tablet vs liquid : harder vs easier to absorb

• enzymes — more enzymes = faster absorption

what happens during the distribution portion of pharmacokinetics

the heart transports drug to site of action via circulation

factors that affect distribution

• hydration status — dehydration = lower circulation

• temperature — warmer = higher circulation

• blood brain barrier — weakened = drug → brain

what happens during the metabolism portion of pharmacokinetics

liver enzymes break down drug into a hydrophilic state

enzyme example from the liver

cytochrome p450 — protects us and breaks down drug

fast past effect

when drug goes through liver and gets metabolized by enzymes

bioavailability

amount of drugs left after first past effect

factors that affect metabolism

• disease — e.g. liver disease = can’t process drugs well

• depot binding — drug binds to fatty tissue = last longer = build up = toxicity

what happens during the excretion portion of pharmacokinetics

removal of drug from the body

methods of excretion

• kidney via urine

• gallbladder via feces

steady state — what is it?

state where amount of drugs absorbed = amount of drugs left after it is removed the body

half life — what is it?

amount of time required for ½ of given drug dose to be removed from the body

how does a drug’s half life affect how we administer it?

if the half life is longer, we administer it less, and vice versa .. this is to achieve steady state!

drugs by mouth — different ways of adminstering

1. swallowing

2. sublingual — placed under tongue, dissolved, no swallow

3. buccal — placed inside cheek, absorbed by membrane, no swallow

if swallowed = less than 100% available because they go into circulatory / absorption! if not swallowed = 100% available

pharmacodynamics definition

what drug does to the body

pharmacodynamics mechanisms

• receptors — drug attaches to receptor

• enzymes — inducers / enhancers & inhibitors

• ligands & g-proteins

• non-selective — affect metabolic process of issues caused by organism

affinity definition

how well drug attaches to receptor

agonist

drug activates response

antagonist

drug prevents response

potency

how much drug is needed to achieve desired effect

efficacy

how well drug will prevent what it’s meant to prevent

onset of action

when does drug begin its action

peak affect

period where drug absorption is at is maximum

trough level

minimum level of drug after distribution, used to see if metabolism and excretion is good

therapeutic index

difference between effective dose and toxic dose which tells us how easily an effective dose can become toxic

adverse drug event (ADE)

any undesirable outcome involving a drug

drug reaction (DR)

an expected but undesired reaction from a therapeutic dose of a drug

anaphylactic reaction

allergic reaction combined with increased heart rate and lowered blood pressure, emergency!

idiosyncratic reaction

unexpected response to normal drug dose due to genetics

tolerance

repeated doses results in decreased effect

dependence

you need the drug to function normally

addiction

using a drug obsessively despite adverse effects

resistance

no longer affected by drug after repeated use

potentiate effect for drugs

one drug enhances the effectiveness of another

additive effect for drugs

two drugs are combined to achieve desired outcome

synergistic effect for drugs

two drugs work better together compared to alone

antagonistic effect for drugs

two drugs counter each other / decrease each others effects

loading dose

drug dose that is higher than what is typically needed for treatment, allowing it to reach its critical concentration sooner

maintenance dose

a drug dose that is lower than what is typically used in order to maintain steady state levels

therapeutic dose

a drug dose that is required to cure a certain disease

prophylactic dose

a drug dose that is used to prevent an unwanted outcome or a disease

empiric dose

treatment type that focuses on preventing a certain disease based on the fact that there is a high chance that the symptoms exhibited by the patient matches that particular disease